SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98aefa622664fcd6db905e2f0e02f25be4ec32b4488b81df22cac44153959b6d' 
  AND token = 'KAMLeMq+zVsdPrPpgoz2lAXbkGU0+LU01K3gawpR78g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}